Oil recommendations for low oil pressure

[tb30570]

And the lowest is what?
What oil are you running now?

The JEGS 555-41450 gage will read zero psi. I'm not sure the gage can accurately read oil pressure that low. Both oil pressure switches tripped, so i assume the pressure is probably lower than 5psi.

I have been running 5w30 synthetic. I added knock-off lucas oil stabilizer by supertech to see if that would help. That delayed the pressure dip, but it still occurs.

 

[Warstud]

The OIl Pressure is probably low because you have an old worn out motor . How many miles does the Envoy have ?

 

[tb30570]

The OIl Pressure is probably low because you have an old worn out motor . How many miles does the Envoy have ?

That's my guess too. Close to 200k.

 

[Warstud]

That's my guess too. Close to 200k.

Thats nothing for that motor . 75 psi is high

 

[tb30570]

I ordered this

 

[blufeb95]

Maybe try something real thick like a heavier 20W50, maybe even straight 50 during the warm months, or dump some of that Lucas "stabilizer" crap in there, maybe the oil pump pressure relief is stuck partially open or is not seating right because it has some gunk in it and running really thick oil that'll help actuate it a frequently and unstick it.

 

[Deleted member 89374]

20W50 will be much cheaper.

Alternatively Mobil 1 15W-50 - available at Walmart.

 

[JavierH19]

I don't agree with this statement, but I would use 5w40 in cold weather, 15w40 in warm weather.

10w-40s have a slightly higher kv100 on average and are ok year round for that engine though i do agree that if it gets cold enough 0/5w-40 should be used but he says 0f like it's as cold as it gets where he's at so that's not too cold. 15w-40's need to be more stable so they're slightly thinner and have less vii. Winters are typically 35f where I'm at so i use 15w-40 year round. But i wouldn't if it got to 0f.

 

[Warstud]

Thicker Oil isn't going to fix nothing .

 

[bhvrdr]

Why not throw in a new oil pump to see if that helps

 

[blufeb95]

Why not throw in a new oil pump to see if that helps

Because to replace the oil pump you have to drop the front axels out and if I remember correctly the steering rack is in the way so you have to move it and then you have to remove all of the front accessories so that you can get the oil pan and timing cover off, it's not a job I'd want to do if I can use bandaids to avoid it.

 

[bhvrdr]

Because to replace the oil pump you have to drop the front axels out and if I remember correctly the steering rack is in the way so you have to move it and then you have to remove all of the front accessories so that you can get the oil pan and timing cover off, it's not a job I'd want to do if I can use bandaids to avoid it.

I don't think these bandaids of changing oil viscosity is going to help with a 0 hot oil pressure condition.

 

[DavidJones]

I'd consider some "oil treatment". Lucas, STP etc. Maybe 2 cans.........

 

[Astro14]

If you’re going to “drive it until it kicks the bucket” then I wouldn’t worry about cold weather performance.

It won’t run long enough with this problem to make it until winter.

If you drop the pan, now, and clean the pickup, then plastigauge the bearings, check the oil pump, and fix what is needed, you might be able to keep it for a while. Years, even.

But your approach isn’t likely to get you more than a couple more months.

So, don’t go spending extra $$ on this in search of a “solution”. The only solution is mechanical repair.

Thicker oil is like a bandaid on a sucking chest wound.

 

[GMBoy]

In a similar situation with a customer's 06 Hummer H3 - which has a variant of that motor just smaller - she was getting tired of the chimes ringing at every stop sign/light due to the low oil pressure. I confirmed she was at best 7psi at idle and probably 5 or less. We discussed her options which she declined due to cost. At that moment I changed her oil and put in Maxlife 10w/40 (the red bottle semi-syn version) with 1 bottle of blue STP and that actually helped and she won't get the low oil pressure warning until a good 3-4000 miles into the oil in which she comes back and we change it again. She just needs the truck to last to the end of the year until she can get a new car.

 

[wlk]

Quaker State All Mileage 10w40 has a CST of 15.7 @100°c. That with a bottle of Schaeffer Moly EP will take it up to a 60ish grade. May try this combo, ran it for a long time in my C1500 until I had the pump changed. Did see they make a 20w50 which by itself may do the trick.

 

[clinebarger]

Why not throw in a new oil pump to see if that helps

On a 4.2L Atlas?.....

 

[zrxkawboy]

Good cleaning oil or a quart of trans fluid to clean the engine up for a few hundred miles

Which ATF contains more detergents than motor oil?

 

[hand-filer]

 

[AdmiralYoda]

Like others have said... heavy oil will be your friend here. 20W-50 in the summer, 5W-50 in the winter if it lasts that long. In the summer I'd add some Lucas oil treatment to thicken it up even more.

As a last ditch effort, though it would likely be a waste of money but might be a fun experiment is to use a very high detergent oil and short OCI's to see if you can clean some junk out of it. Maybe a run of HPL PCMO with a quart of their engine cleaner. Change the filter every 2k miles or so. Then run some HPL CK-4 Heavy Duty or Passenger Car Oil at 20W-50.

If the low pressure is pump related due to gunk buildup...this may help.